The present invention relates to saggers employed in the firing of ceramic articles in a kiln.
Most saggers in commercial use today comprise rigid rectangular boxes of unitary construction with an open top for receiving the green ceramic articles placed therein for subsequent firing. Such saggers are adapted to be stacked vertically in the kiln during firing.
The difficulty with these conventional saggers resides in the fact that when subject to extreme temperature variations during use, they expand and contract and frequently warp and thus become very difficult to stack or even worse, break, rendering them unusable. It is not economically feasible to repair such saggers.
Some attempts have been made to relieve the difficulty encountered with unitary sagger construction. Such efforts are represented by U.S. Pat. Nos. 2,297,286 issued on Sept. 29, 1942 to A. R. Book; 1,186,490 issued on June 6, 1916 to H. Moorcroft and 287,469 issued on Oct. 30, 1883 to S. Pulson and M. L. Snow.
In such sagger construction, although some of the difficulties encountered with the unitary construction have been alleviated by providing multiple piece saggers having joints, the sagger construction either is so complex as to be very expensive to manufacture, or the loosely fitting joints of the individual pieces of the sagger do not provide sufficient stability for movement of the sagger during use, particularly when loaded with green pieces. As a result, the unitary sagger construction although undesirable, still remains the industry standard largely due to the failure of the prior art to provide an economical multiple section sagger which provides the structural characteristics required by the sagger and also overcomes the deficiencies of the single piece sagger in common use.